1. Field of the Invention
This invention relates to cover stocks for golf balls offering a good feel when hit and having improved scuff resistance. More particularly, it relates to cover stocks suitable for the manufacture of golf balls which offer a very soft feel without exhibiting a shock when hit with a driver and exhibit improved scuff resistance against iron shots without detracting from the ease of control upon approach shots.
2. Prior Art
In prior art golf balls, balata or trans-polyisoprene is often used as the cover stock. Professional and skilled golfers prefer golf balls using balata as the cover stock, because the balata cover balls are good in feel upon full shots with a driver and the ease of control (or spin susceptibility) upon approach shots.
The balata cover balls, however, have the drawback that the ball surface is marred or fluffed as a consequence of iron shots because the cover surface can be scraped by grooves across the iron club face. In addition, balata is expensive and low in productivity because of the difficulty to mold.
For overcoming these drawbacks of balata, a variety of cover stocks using thermoplastic polyurethane elastomers have been proposed (U.S. Pat. Nos. 3,395,109, 4,248,432, and 4,442,282).
Since thermoplastic polyurethane elastomers used as the cover stock are not only improved in feel and control like balata, but also inexpensive and easy to mold, these elastomers are regarded as an excellent cover stock substitute for the balata material. However, the thermoplastic polyurethane elastomers are still insufficient in scuff resistance upon iron shots. Particularly at low temperatures or in winter, there is a likelihood that the ball surface can be cracked and dimples will be scraped off by the iron club face.
There is a desire to develop a cover stock suitable for the manufacture of high performance golf balls which exhibit improved scuff resistance against iron shots without detracting from the ease of control upon approach shots, and offer a very soft feel without shocks when hit.